Some details

I did not receive a Fortune Fee from the quest. You probably just did it during the receive time.

IIRC all receive times were 30/60 min since you were logged in, and relogging/changing channels resets that.

I think they made this event not afk-able.. I did not seem to receive any extra fee's after I had two in my inventory... Will have to wait longer to be sure.

I agree, the description from the event made it seem like it was based on when you logged in and every time after, but I do suspect it's every 30 minutes on the server time.

All receive times were 30/60 min since you were logged in, and relogging/changing channels resets that.

I literally afked 4 hours for it and I got 8 fortune fees just as plannned lol.

I also have been getting them while afk. They do seem to conflict with the homestead event though. If your inventory is full they go into your temporary inventory with no time limit to reclaim. Once they do this they cancel any loaded skill such as fishing, thus making it impossible to afk fish for more than a couple hours without checking in.

Cheap trick to do both events at once: Get a Candy Jar in your inventory. Make every other open slot in your inventory 1x1, like a checkerboard. That way the Candy Jars will auto-stack, and the Fortune's Fees will fill all the open slots. The only things you can fish up that are 1x1 are the tiny fish that stack and potions.